Two Element Antenna Array

Introduction

• Explanation of two-element antenna array
• Brief reference to previous video on n-element antenna array and electric field/array factor calculations

Antenna Structure

• Two elements in the antenna array: Element 1 (reference) and Element 2
• Reference element connected with zero phase; second element with phase of alpha
• Amplifiers and power divider circuit in place
• Antenna elements radiate in space
• Antenna axis and angle theta (Θ) defined

Phase Difference Calculation

• Path difference between two antenna elements is D cos(Θ)
• For λ distance, phase difference is 2π
• Phase difference for D cos(Θ):
  • Formula: ((2π / λ) * D cos(Θ))
  • Adding initial phase (α): Phase difference (S) = (\frac{2π}{λ}D cos(Θ) + α)
  • Simplified to: (βD cos(Θ) + α)

Electric Field Calculation

• Origin (O) considered at a specific point in structure
• Phase leading/lagging:
  • Element 1 leads by (\frac{S}{2})
  • Element 2 lags by (\frac{S}{2})
• Electric field equations:
  • Field of Element 1: (E_1 = E * e^{\frac{jS}{2}})
  • Field of Element 2: (E_2 = E * e^{-\frac{jS}{2}})
• Total Electric Field: Sum of electric fields
  • (E_{total} = 2E * cos(\frac{S}{2}))

Array Factor Calculation

• Array Factor = Total Electric Field / Electric Field due to one element
• (AF = \frac{2E * cos(\frac{S}{2})}{E} = 2 cos(\frac{S}{2}))
  • where S = (βD cos(Θ) + α)

Relationship to n-Element Array

• Reference to electric field and array factor for n-element arrays
• Derivation using n-element array formulas:
  • (AF_n = \frac{sin(nS/2)}{sin(S/2)})
  • For n=2:
    • (AF_2 = \frac{sin(2S/2) * cos(S/2)}{sin(S/2)})
  • Simplifies to: (2 cos(\frac{S}{2}))

Future Topics

• Upcoming explanations on other parameters:
  • Location of Maxima and Minima
  • Half Power Beam Width
  • First Null Beam Width

Conclusion

• Invitation for comments and questions
• Gratitude for watching